两型棘球蚴感染早期对肝组织自噬和肝巨噬细胞极化的影响

Effects of early infection with Echinococcus granulosus and Echinococcus multilocularis on autophagy and Macrophage cell polarization in liver

目的 明确细粒棘球蚴和多房棘球蚴感染早期对小鼠肝脏自噬相关蛋白及巨噬细胞极化的影响。方法 购雌性BALB/C小鼠18只,随机分为实验组与对照组。实验组分别接种细粒棘球绦虫和多房棘球绦虫原头蚴,感染30 d后解剖小鼠,取肝脏,切片,通过HE染色观察两型棘球蚴感染后小鼠肝脏病理学变化,利用免疫组化法和Western blot检测小鼠肝脏中自噬相关蛋白的表达,采用流式细胞术检测肝脏M1和M2巨噬细胞比例。结果 感染细粒棘球蚴和多房棘球蚴30 d小鼠肝脏病灶面积和病灶数量存在差异,免疫组化检测细粒棘球蚴和多房棘球蚴感染小鼠肝脏自噬相关蛋白LC3、P62相对表达量分别为(7.34±2.33)%、(15.19±8.37)%和(16.09±6.43)%、(11.46±3.81)%,与对照组比较差异均有统计学意义(P<0.05)。Western blot检测显示多房棘球蚴感染组LC3蛋白表达量(1.08±0.20)%显著高于细粒棘球蚴感染组的(0.53±0.29)%(P<0.05)。细粒棘球蚴组和多房棘球蚴组的肝脏巨噬细胞比例为(29.20±8.05)%(26.47±4.58)%,M1型巨噬细胞比例分别为(42.93±20.76)%和(43.93±14.16)%,均显著高于对照组。M2型巨噬细胞比例分别为(9.45±2.61)%和(6.09±0.09)%,显著低于对照组(P<0.05)。结论 细粒棘球蚴和多房棘球蚴早期感染均促进小鼠肝脏自噬相关蛋白的表达,使巨噬细胞向M1型极化,同时抑制M2型极化。自噬可能在早期参与减轻炎症反应,帮助机体清除病原体。

Objective To investigate the effect of early infection of Echinococcus granulosus and Echinococcus multi-locularis on autophagy related proteins and macrophage polarization in mouse liver.Methods 18female BALB/C mice were purchased and randomly divided into an experimental group and a control group.The experimental group was inocu-lated with protoscoleces of E.granulosus and E.multilocularis respectively.After 30days of infection,mice were dissec-ted,and their livers were sectioned.HE staining was used to observe the pathological changes;immunohistochemistry and Western blot were used to detect the expression of autophagy related proteins(LC3and P62),and flow cytometry was used to detect the proportion of M1and M2macrophages in the liver of mice infected with two echinococcoses.Results The results showed that there were differences in the pathological responses and number of liver lesions between mice in-fected with E.granulosus and E.multilocularis at 30days of post-infection.Immunohistochemical detection revealed that LC3was(7.34±2.33)%and(15.19±8.37)%,P62was(16.09±6.43)%and(11.46±3.81)%in the liver of mice infec-ted with E.granulosus and E.multilocularis,respectively,which are statistical significance compared to the control group(P<0.05).Western blot analysis showed that LC3in E.multilocularis infected mice(1.08±0.20)%was signifi-cantly higher than that in mice infected with E.granulosus(0.53±0.29)%(P<0.05).The proportion of liver macrophages was(29.20±8.05)%and(26.47±4.58)%,and the proportion of M1macrophages was(42.93±20.76)%and(43.93±14.16)%,respectively in E.granulosus and E.multilocularis infected mice,which were significantly higher than that the control group(P<0.05);The proportion of M2macrophages was(9.45±2.61)%and(6.09±0.09)%,respec-tively E.granulosus and E.multilocularis infected mice,which were significantly lower than that of the control group(P<0.05).Conclusion Early infection with E.granulosus and E.multilocularis promotes the expression of autophagy related proteins in mouse livers,inducing M1polarized macrophages which likely inhibit M2macrophages.This mecha-nism may be involved in alleviating inflammatory reactions in the liver lesions and helping hosts to clean pathogens in the early stages.